This invention pertains to display devices and, more particularly concerns display devices that are configured for use in serial, sequential reading applications.
Display devices come in many shapes and sizes and can be implemented using different types of technologies. One particular type of display device is one that enables a user to read various types of materials such as text (e.g. books, magazines, and newspapers) maps, drawings, and the like, while maintaining a desirable degree of portability. For example, in recent times, there has been a push by the industry to provide so-called electronic xe2x80x9creadersxe2x80x9d so that users might be able to read an electronic version of a favorite book or newspaper.
The design of electronic readers requires an appreciation and consideration of several factors that directly affect the popularity and commercial marketability of the electronic reader. In order to meet the demands of very discriminating consumers, and to provide an economically sensibly-manufactured product, electronic readers should or must: (1) be small enough to be conveniently portable, (2) have a desirable degree of contrast so that the user can easily read content that is displayed by the reader, (3) have a high degree of resolution so that the images displayed by the reader are crisp and clear, (4) have low power consumption characteristics to reduce the overall footprint within the device of the power supply component as well as to provide a desirably long lifetime for a given power supply, and (5) have a low enough cost so that it can be widely available for purchase by many consumers.
There are different technologies that are available for manufacturing various types of display devices among which include CRT (cathode ray tube) technologies, LCD (liquid crystal display) technologies, FEDs (field emission display) technologies, and so called xe2x80x9cE-inkxe2x80x9d technologies.
CRT technologies are limited, to a large extent, by the contrast that is able to be provided, the size requirements of the displays, the power consumption, resolution and cost. This technology is not a logical choice for conveniently portable electronic readers. LCD technologies typically have complicated electronics and display componentry and do not achieve a desired degree of resolution at a cost that is acceptable to compete in the display reader market. The same can be said of FED technologies.
There is a continuing unmet need for display readers that meet all or some of the criteria discussed above. It would be highly desirable to provide such a display reader that can display content from a number of various sources, such as the Web, a database, a server, and the like, and do so in a manner that satisfies or accommodates the needs of our biological system (i.e. eyes) for resolution, contrast, speed of image generation for reading and the like. Accordingly, the present invention arose out of concerns associated with meeting some or all of these needs.
Electronic display devices and methods are described. In one embodiment, a display device comprises a housing with a display area to display content for a user. Memory within the housing holds data that is to be rendered into user-viewable content. A loop of material is provided within the housing and is configured to display user-viewable content for the user. The loop of material is provided as a photosensitive material, with an exemplary material comprising indium tin oxide. An exposure station is provided internally of the loop of material and is configured to expose selected portions of the loop of material so that the loop of material can receive and retain toner thereon to provide the user-viewable content from the data that is held in the memory.
In another embodiment, a display device comprises a toner shuttling system within the housing that is configured to shuttle toner between different locations within the housing from which the toner can be used and reused. The shuttling system, in one implementation, takes the form of multiple toner reclamation/development stations, each of which being configured to operate to either reclaim toner or develop toner. The stations are desirably configured so that when one station operates to reclaim toner, another station operates to develop toner. In one particular implementation, the stations comprise a pair of switchably-biasable, bi-modal reclamation/development stations where, in one mode, a station develops toner and, in the other mode, the station reclaims used toner. Reclamation of toner can advantageously take place through non-invasive techniques, e.g. electrostatic techniques.
In one methodical embodiment, a toner processing method comprises providing a loop of photosensitive material within a display device. The loop of photosensitive material is moved in a direction and charged to provide a charge distribution throughout portions of the loop of material. The loop of photosensitive material is exposed to light energy from an exposure station positioned internally of the loop sufficient to change the charge distribution throughout portions of the loop of photosensitive material. Responsive to the exposure, toner is developed onto the loop of photosensitive material to provide an image which is moved into a display area where it can be viewed. Toner that was developed onto the loop of photosensitive material to provide the image is then reclaimed for reuse. Reclamation of the toner can advantageously take place through non-invasive techniques, e.g. electrostatic techniques.